Consolidated Statements of Earnings - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016	[1]
Income Statement [Abstract]
Revenue from services	$ 5,374.4	$ 5,276.8	$ 5,518.2
Cost of services	4,420.3	4,370.5	4,597.9
Gross profit	954.1	906.3	920.3
Selling, general and administrative expenses	870.8	843.1	853.6
Earnings from operations	83.3	63.2	66.7
Gain on investment in PersolKelly Asia Pacific	0.0	87.2	0.0
Other expense, net	(1.6)	(0.7)	(3.5)
Earnings before taxes and equity in net earnings (loss) of affiliate	81.7	149.7	63.2
Income tax expense	12.8	30.0	8.7
Net earnings before equity in net earnings (loss) of affiliate	68.9	119.7	54.5
Equity in net earnings (loss) of affiliate	2.7	1.1	(0.7)
Net earnings	$ 71.6	$ 120.8	$ 53.8
Basic earnings per share	$ 1.84	$ 3.10	$ 1.39
Diluted earnings per share	1.81	3.08	1.39
Dividends per share	$ 0.30	$ 0.275	$ 0.20
Average shares outstanding (millions):
Basic (in shares)	38.3	38.1	37.8
Diluted (in shares)	39.0	38.4	37.9

[1] Fiscal year included 53 weeks.